As a Chinese unique rare plant, Camellia nitidissima Chi has good reputation of “Giant Panda of Botany” and “Emperor in Theaceae”. In civil history, it was recorded in Compendium of Materia Medica, and also in Local Chronicle of Gangdong and Guangxi that “Camellia nitidissima Chi, evergreen shrub, grow in wildemess”, “the leaves and flowers of Camellia nitidissima Chi can be used for heat-clearing, the treatment of dysentery, lipid-removing and hypoglycemia”. In folk of Guangdong and Guangxi area, Camellia nitidissima Chi is widely used to make tea or cook soup for clearing heat and removing toxicity, lipid-lowering and hypoglycemia, diuresis, dehydration and depressurization over thousands of years, so the lipid-lowering and hypoglycemic effect of Camellia nitidissima Chi has profound inherent foundation.
At present, there exist some theories and practice researches on Camellia nitidissima Chi lipid-lowering and hypoglycemic effect, for example, crude polysaccharide is primary separated by deproteinization and dialysis, then mice with hyperlipidemia are fed into the primary separated polysaccharide, experiment data shows high dose group, middle dose group and low does group of Camellia nitidissima Chi polysaccharide can all reduce TC, TG and LDL-C level of serum in the mice with hyperlipidemia dramatically and enhance mice with hyperlipidemia ratio. After two weeks of intragastric gavage, the TC level of serum of the mice can all reach normal level, and the effect is better than Xuezhikang capsule. Test results show Camellia nitidissima Chi polysaccharide is capable of obvious lipid-lowering function. (Lu Wei, Xiaoming Qin, Huajuan Lin, Enchuang Ning, Hong Yang. Study on Lipid-lowering Function of Camellia Nitidissima Polysaccharide); Enchuang Ning and co-workers feed Wistar rat with high-lipid diet for 15 days to make model of rat with hyperlipidemia, then intragastric gavage is performed with Camellia nitidissima Chi leaves aqueous extract respectively by 0.8 g/kg, 0.4 g/kg, and 0.2 g/kg, lovastatin (0.01 g/kg), the clinical lipid-lowering drug, is used for positive control. After 43 days of intragastric gavage, the serum is collected to test the total cholesterol (TC), tri glyceride (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C). Results show both high dose group and middle dose group of Camellia nitidissima Chi leaves aqueous extract can reduce TC, TG and LDL-C content of serum in model rat with hyperlipidemia, the effect of which is equivalent to that of lovastatin, compared with the hyperlipidemia group, both the differences of high dose group and middle dose group have significance through test; high dose group and lovastatin can also enhance HDL-C content of serum in model rat with hyperlipidemia. So it shows the Camellia nitidissima Chi leaves aqueous extract have obvious lipid-lowering effect. (Enchuang Ning, Xiaoming Qin, Hong Yang. Experimental Study on Lipid-lowering Function of Camellia Nitidissima Leaves Aqueous Extract. Journal of Guangxi university (Nature and Science), 2004, 29(4), 350-352); Yonglin Huang and co-workers feed quail with high-lipid diet for 15 days to make model of quail with hyperlipidemia, then intragastric gavage is performed with 400 mg/kg Camellia nitidissima Chi leaves extract, fenofibrate tablets (20 mg/kg), the clinical lipid-lowering drug, is used for positive control, after 30 days of intragastric gavage, the serum is collected to test the total cholesterol (TC), tri glyceride (TG) content. Both the Camellia nitidissima Chi leaves extract and primary purified extract can reduce TC and TG content of serum in model quail with hyperlipidemia, while the ethanol extract can only reduce the TC content. Camellia nitidissima leaves extract have lipid-lowering effect and can perform enrichment with D-101 resin. (Yonglin Huang, Yueyuan Chen, Yongxin Wen, Dianpeng Li, Ronggan Liang, Xiao Wei. Experimental Study on Lipid-lowering Function of Different Solutions and Primary Purified Camellia Nitidissima Leaves Extract. Lishizhen Med Mater Med Res, 2009, 20(4), 776-777).
Diabetic mice models were established by intravenous injection of alloxan tetrahydrate by Xing Xia and co-workers, and the mice are divided into model group, metformin group, high dose group, middle dose group and low dose group of Camellia nitidissima Chi extract, while normal mice are the blank control group, then intragastric gavage is performed continually for 28 days and determine fasting blood-glucose before and after dosing of the 7th day, 14th day, 21th day and 28th day respectively, and after the final determination of fasting blood-glucose, 6 g/kg glucose solution is fed by gavage to all animals, then blood glucose level is determined after 30 min, 60 min and 120 min to inspect glucose tolerance levels of animals. Results show it can reduce the fasting blood-glucose (P<0.001) of diabetic mice dramatically after one week of dosing Camellia nitidissima Chi leaves extract, but only hypoglycemic effect of high dose group can continue, until 4 weeks of dosing, both high dose group and low dose group can reduce the blood-glucose (P<0.05) of diabetic mouse dramatically. In glucose tolerance experiment, Camellia nitidissima Chi leaves extract can inhibit the increase of blood glucose (P<0.001) after the meal, after 120 min of the meal, the blood glucose can be reduced to the level before the meal. A conclusion came to that Camellia nitidissima Chi leaves extract has lipid-lowering effect on alloxan-induced hyperglycemic mice due to low toxicity, so it may be used to help control blood glucose level of diabetic patients. (Xing Xia, Jiajun Huang, Zhiping Wang, Qin Wang, Weigao Pan. Hypoglycemic Effect and Acute Toxicity of Camellia Nitidissima Leaves. Lishizhen Med Mater Med Res, 2013, 5, F0003-F0004); diabetic mice models were established by intravenous injection of alloxan tetrahydrate by researchers, and the mice are divided into model group, metformin group, high dose group, middle dose group and low dose group of Camellia nitidissima Chi extract, while normal mice is the blank control group, then intragastric gavage is performed continually for 28 days, and after the final dosing, the fasting insulin levels are determined, change of the pancreas organization structure is observed by using HE staining, moreover, hepatic glycogen and hepatic glycogen level are determined. Data shows Camellia nitidissima Chi leaves extract can improve the insulin level (P<0.05) of diabetic mouse, relieve pancreas pathological lesion, and improve hepatic glycogen reserve (P<0.05) dramatically. Results show Camellia nitidissima Chi extract can improve pancreas structure and function, in this way, the lipid-lowering effect of Camellia nitidissima Chi extract can be played well. (Xing Xia, Chuanshen Pan, Lin Huang, Zhiping Wang, Qin Wang, Weigao Pan. (Hypoglycemic Effect and Acute Toxicity of Camellia Nitidissima Leaves. Lishizhen Med Mater Med Res, 2013, 12, 2863-2865).
In clinical study of Harbor Hospital of Beihai in Guangxi and Guangxi University in September 2003, they found Camellia nitidissima Chi products have good lipid-lowering and blood glucose regulating effect. There are 87 employees (including retired employees) in the test study in September, including many people with hyperglycemia and diabetic. The total cholesterol of chosen cases is more than 5.22 mmol/L (220 mg/dl), and triglyceride is more than 1.70 mmol/L (150 mg/dl). Patients aged 40 to 72, with 4-15 years medical history, all belong to secondary and tertiary “3-H diseases”, that is, hyperlipidemia, hypertension and hyperlipidemia. After 30 days of taking camellia nitidissima, the subjective symptoms of 37 patients, occupying 88%, are improved obviously, symptoms like headaches, dizziness, tinnitus and precordium pain are disappeared, palpitation and compressive feeling are relieved, and weight is also reduced. The blood lipid is reduced generally. They are in good physical condition after 60 days, uncomfortable symptoms over years are disappeared, and the lipid is lowered to normal level. At the same time of lipid-lowering, the health condition turns good to varying degrees, many people insist on taking it throughout the year.
Above literatures or reports show that Camellia nitidissima Chi has unique advantages in lipid-lowering and hypoglycemic effect, the lipid-lowering effect is even better than the common medicine, clofibrate. The experimental animals which are fed into high-lipid food exist symptoms like deposition of aortic focal lipid, proliferation of fibrous tissue, increase of elastic lamina, and thickening of arterial wall; while for the experiment group fed into camellia nitidissima, above symptoms are smaller than control group obviously. So it demonstrates that Camellia nitidissima Chi has a remarkable effect on lowering lipid and cholesterol due to rich active components in camellia nitidissima, like tea polysaccharides. On the other hand, Camellia nitidissima Chi has a remarkable effect on hypoglycemia due to rich active components in camellia nitidissima, like tea polyphenols and flavones.
Many existing technologies study on the Camellia nitidissima Chi lipid-lowering and hypoglycemic pharmacology or lipid-lowering and hypoglycemic effect of Camellia nitidissima Chi aqueous extract or alcohol extract generally, while few technologies refer to the application fields like development and preparation of dosage forms of drug or health products. Besides, the best clinical or health care effect of lipid-lowering and hypoglycemic active components in Camellia nitidissima Chi can not be played to the fullest through the general study on lipid-lowering and hypoglycemic effect. In fact, only one or several kinds of key components in active components play the role of lipid-lowering and hypoglycemic effect, while others can not help to lower the lipid and reduce blood glucose, even to interfere curative effect or health care effect. For example, other components in Camellia nitidissima Chi like saponin, vanillin, ionone, phytol, α-spinasterol, arbricolin, hexadecyl-oxiran, myristic acid, α-Amyrin and β-Amyrin may greatly affect the lipid-lowering and hypoglycemic effect. In the development of pharmaceutical preparations, it is necessary to separate main lipid-lowering and hypoglycemic active components respectively and combine based on actual lipid-lowering and hypoglycemic clinical requirements to prepare various kinds of lipid-lowering and hypoglycemic agents.